It was actually Klingon so I guess it's supposed to be ugly. I like it though. Looks very functional.
Well, it was greenish. But it also had a Starfleet logo on its side. A Klingon design purchased by Starfleet?
I can make out a similar underside in HD screencaps of it in FC.
Looks like it, yeah. This is the Fact Files rendition:
Whether that's "Defiant
-like" is debatable. The same seven-cornered hatches are there, but otherwise it's just generic aztecing... If we're to define design age by similarities of this sort, the Akira
was built in the 2150s!